I have this formula

(if OnFirstRecord then
   {@HR File Header Layout} + chr(13) + chr(10)
else
   '') +

{@DR Record Layout} +
( If {@LN Amount} <> 0 then
        chr(13) + chr(10) + {@LN Record Layout}
    else
        '';) +
(if OnLastRecord then
   chr(13) + chr(10) + {@FF Record Layout}
else
   '');


and I get this error A String is required here

Right after <>0

What I'm I missing

thanks